1. Field of the Invention
The present invention relates to an image forming apparatus, for forming an image on a recording medium, to which a cartridge can be detachably attached.
2. Description of the Related Art
An image forming apparatus is configured to form an image on a recording medium by employing an image forming process such as an electrophotographic process, an electrostatic recording process, or a magnetic recording process. The image forming apparatus includes, for example, a copying machine, a printer (a light-emitting diode (LED) printer, a laser beam printer or the like), a facsimile apparatus, and a multifunction peripheral having the functions of the above-mentioned apparatuses. An image is formed on the recording medium by the image forming apparatus. The recording medium includes, for example, paper, an overhead transparency (OHT) sheet, or a label.
The cartridge includes, for example, a process cartridge or a development cartridge, and contributes to an image forming process for forming an image on a recording medium while being detachably attached to the apparatus main body of the image forming apparatus. The apparatus main body refers to the components of the image forming apparatus excluding the cartridge.
The process cartridge is formed by integrating an image bearing member, on which a latent image is to be formed, with at least one of the following units: a charging unit, a developing unit, a cleaning unit, etc., and is detachably attached to the apparatus main body. The image bearing member includes an electrophotographic photosensitive member for an electrophotographic process, an electrostatic recording dielectric for an electrostatic recording process, a magnetic recording magnetic member for a magnetic recording process or the like. The process cartridge can be attached and detached to and from the apparatus main body manually by the user. Thus, the maintenance of the apparatus main body is easy to perform.
Accordingly, the process cartridge includes a cartridge in which an image bearing member is integrated with a process unit, and is detachably attached to an apparatus main body. The process cartridge in which the image bearing member and the developing unit are integrated is referred to as an integrated-type process cartridge. The process cartridge in which the image bearing member and a process unit excluding the developing unit is integrated is referred to as a separated-type process cartridge. That is, the separated-type process cartridge refers to a cartridge which performs image formation along with the development unit, which is provided separately from the process cartridge.
The development cartridge includes a developing roller (developer bearing member) and contains developer (toner) used for developing a latent image formed on the image bearing member. The development cartridge is detachably attached to the apparatus main body. The development cartridge can also be attached and detached to and from the apparatus main body manually by the user. Thus, the maintenance of the apparatus main body is easy to perform.
In the case of the development cartridge, the image bearing member is mounted to the apparatus main body or a cartridge support member. Alternatively, the image bearing member is provided in the separated-type process cartridge (In this case, the process cartridge does not include the developing unit).
Thus, the cartridge includes the integrated-type or the separated-type process cartridge. Further, the case is included where the separated-type process cartridge and the development cartridge are used together in pairs. Further, the case is included where the image bearing member is fixedly mounted to the apparatus main body or the cartridge support member, with the development cartridge being detachable so as to be capable of acting on the image bearing member. Further, the cartridge also includes a developer cartridge containing developer (toner) to be supplied to the process cartridge, the development cartridge, etc.
For the sake of convenience in illustration, an electrophotographic image forming apparatus employing electrophotography such as a printer will be used as an example for description. An electrophotographic photosensitive member serving as the image bearing member is uniformly charged, and a latent image is formed through selective exposure of the electrophotographic photosensitive member. The latent image is developed with the developer to be visualized as a developer image, and then the image is transferred to a recording medium. By applying heat and pressure to the transferred developer image, the image is fixed and recorded onto the recording image.
Such an electrophotographic image forming apparatus involves the supply of developer and the maintenance of various process units. As a means for facilitating the developer supply operation and the maintenance, all or part of the electrophotographic photosensitive member, the charging unit, the developing unit, the cleaning unit, etc., are integrated into a frame as a cartridge. There is adopted a cartridge system in which the cartridge is detachably attached to the apparatus main body of the electrophotographic image forming apparatus.
In this cartridge system, the maintenance of the apparatus can be performed by the user in such a way as to replace the cartridge, thereby achieving a substantial improvement in terms of operability. Thus, this cartridge system is widely used in electrophotographic image forming apparatuses.
In this connection, there is provided a description of an electrophotographic image forming apparatus in which a plurality of cartridges are arranged in a substantially horizontal direction. To facilitate the attachment and detachment of the cartridge with respect to this electrophotographic image forming apparatus, there has been proposed a pull-out configuration in which a plurality of cartridges are integrally pulled out (as discussed in Japanese Patent Application Laid-Open No. 2010-122661). Further, Japanese Patent Application Laid-Open No. 2010-122661 discusses a configuration for achieving a reduction in size of the apparatus main body and securing the replaceability of the cartridge. That is, when a pull-out member is pulled out, the front edge position thereof is situated on the inner side of the front edge position of an opening/closing member. Further, for the attachment and detachment of the cartridge on the upstream side in the pull-out direction supported by the pull-out member, an opening is provided vertically above the apparatus main body. The opening/closing member has a surface curved in an arcuate shape so that, when closed, the opening/closing member can cover an opening provided in the horizontal direction and the opening provided in the vertical direction.
The present invention further improves the above-described conventional technique.
In the related-art configuration, as illustrated in FIG. 2 of Japanese Patent Application Laid-Open No. 2010-122661, when the opening/closing member is opened, the opening/closing member enters the pull-out region of the sheet feeding cassette. That is, when a cassette accommodating sheets having a length larger than that of the apparatus main body (such as A3 size sheets or legal size sheets) is mounted, the cassette will interfere with the opening/closing member. Further, when an attempt is made to further reduce the size in the vertical direction of the image forming apparatus, there is the possibility of interference between the installation surface of the image forming apparatus and the opening/closing member. That is, to solve these problems, it is necessary to diminish the opening provided vertically above the apparatus main body, and to increase the pull-out amount so that the cartridge on the upstream side in the pull-out direction supported by the pull-out member can be attached and detached.